[CFE/kernel] Generate dart files with versions in them from tools/experimental_features.yaml

Use the version from tools/experimental_features.yaml as the current
language version (as specified in kernel).

Use the "enabledIn" from tools/experimental_features.yaml to write out
the major and minor version for enabling features. This replaces the
hard-coding of when nnbd is enabled (in front-end).

Change-Id: I5b5dd7c2bb0c1a412ef1e660dfbe61e227193e1b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/138284
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>

pkg/front_end/lib/src/api_prototype/compiler_options.dart

@@ -7,7 +7,8 @@ library front_end.compiler_options;
 import 'package:_fe_analyzer_shared/src/messages/diagnostic_message.dart'
     show DiagnosticMessageHandler;
 
-import 'package:kernel/ast.dart' as kernel show Library;
+import 'package:kernel/default_language_version.dart' as kernel
+    show defaultLanguageVersionMajor, defaultLanguageVersionMinor;
 
 import 'package:kernel/target/targets.dart' show Target;
 
@@ -243,9 +244,9 @@ class CompilerOptions {
   /// The current sdk version string, e.g. "2.6.0-edge.sha1hash".
   /// For instance used for language versioning (specifying the maximum
   /// version).
-  String currentSdkVersion = "${kernel.Library.defaultLanguageVersionMajor}"
+  String currentSdkVersion = "${kernel.defaultLanguageVersionMajor}"
       "."
-      "${kernel.Library.defaultLanguageVersionMinor}";
+      "${kernel.defaultLanguageVersionMinor}";
 }
 
 /// Parse experimental flag arguments of the form 'flag' or 'no-flag' into a map

pkg/front_end/lib/src/api_prototype/experimental_flags.dart

@@ -19,6 +19,25 @@ enum ExperimentalFlag {
   variance,
 }
 
+const int enableConstantUpdate2018MajorVersion = 2;
+const int enableConstantUpdate2018MinorVersion = 4;
+const int enableControlFlowCollectionsMajorVersion = 2;
+const int enableControlFlowCollectionsMinorVersion = 2;
+const int enableExtensionMethodsMajorVersion = 2;
+const int enableExtensionMethodsMinorVersion = 6;
+const int enableNonNullableMajorVersion = 2;
+const int enableNonNullableMinorVersion = 8;
+const int enableNonfunctionTypeAliasesMajorVersion = 2;
+const int enableNonfunctionTypeAliasesMinorVersion = 8;
+const int enableSetLiteralsMajorVersion = 2;
+const int enableSetLiteralsMinorVersion = 2;
+const int enableSpreadCollectionsMajorVersion = 2;
+const int enableSpreadCollectionsMinorVersion = 2;
+const int enableTripleShiftMajorVersion = 2;
+const int enableTripleShiftMinorVersion = 8;
+const int enableVarianceMajorVersion = 2;
+const int enableVarianceMinorVersion = 8;
+
 ExperimentalFlag parseExperimentalFlag(String flag) {
   switch (flag) {
     case "constant-update-2018":

pkg/front_end/lib/src/fasta/source/source_library_builder.dart

@@ -51,6 +51,9 @@ import 'package:kernel/ast.dart'
         VariableDeclaration,
         VoidType;
 
+import 'package:kernel/default_language_version.dart' as kernel
+    show defaultLanguageVersionMajor, defaultLanguageVersionMinor;
+
 import 'package:kernel/class_hierarchy.dart' show ClassHierarchy;
 
 import 'package:kernel/clone.dart' show CloneVisitorNotMembers;
@@ -165,9 +168,8 @@ import 'source_extension_builder.dart' show SourceExtensionBuilder;
 
 import 'source_loader.dart' show SourceLoader;
 
-// TODO(johnniwinther,jensj): Replace this with the correct scheme.
-const int enableNonNullableDefaultMajorVersion = 2;
-const int enableNonNullableDefaultMinorVersion = 8;
+import '../../api_prototype/experimental_flags.dart'
+    show enableNonNullableMajorVersion, enableNonNullableMinorVersion;
 
 class SourceLibraryBuilder extends LibraryBuilderImpl {
   static const String MALFORMED_URI_SCHEME = "org-dartlang-malformed-uri";
@@ -383,8 +385,8 @@ class SourceLibraryBuilder extends LibraryBuilderImpl {
   @override
   bool get isNonNullableByDefault =>
       loader.target.enableNonNullable &&
-      languageVersion.major >= enableNonNullableDefaultMajorVersion &&
-      languageVersion.minor >= enableNonNullableDefaultMinorVersion &&
+      languageVersion.major >= enableNonNullableMajorVersion &&
+      languageVersion.minor >= enableNonNullableMinorVersion &&
       !isOptOutPackage(library.importUri) &&
       !isOptOutTest(library.importUri);
 
@@ -3958,10 +3960,10 @@ class InvalidLanguageVersion implements LanguageVersion {
       this.fileUri, this.charOffset, this.charCount, this.isExplicit);
 
   @override
-  int get major => Library.defaultLanguageVersionMajor;
+  int get major => kernel.defaultLanguageVersionMajor;
 
   @override
-  int get minor => Library.defaultLanguageVersionMinor;
+  int get minor => kernel.defaultLanguageVersionMinor;
 
   @override
   bool get valid => false;
@@ -3983,10 +3985,10 @@ class ImplicitLanguageVersion implements LanguageVersion {
   const ImplicitLanguageVersion();
 
   @override
-  int get major => Library.defaultLanguageVersionMajor;
+  int get major => kernel.defaultLanguageVersionMajor;
 
   @override
-  int get minor => Library.defaultLanguageVersionMinor;
+  int get minor => kernel.defaultLanguageVersionMinor;
 
   @override
   bool get valid => true;

pkg/front_end/test/language_versioning/language_versioning_up_to_date_test.dart

@@ -3,8 +3,11 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:io' show Platform, Process, ProcessResult;
+
 import 'package:front_end/src/api_prototype/compiler_options.dart';
-import 'package:kernel/ast.dart' as kernel show Library;
+
+import 'package:kernel/default_language_version.dart' as kernel
+    show defaultLanguageVersionMajor, defaultLanguageVersionMinor;
 
 import '../utils/io_utils.dart';
 
@@ -34,12 +37,12 @@ main(List<String> args) async {
   int major = int.tryParse(dotSeparatedParts[0]);
   int minor = int.tryParse(dotSeparatedParts[1]);
 
-  if (kernel.Library.defaultLanguageVersionMajor != major ||
-      kernel.Library.defaultLanguageVersionMinor != minor) {
+  if (kernel.defaultLanguageVersionMajor != major ||
+      kernel.defaultLanguageVersionMinor != minor) {
     throw "Kernel defaults "
-        "${kernel.Library.defaultLanguageVersionMajor}"
+        "${kernel.defaultLanguageVersionMajor}"
         "."
-        "${kernel.Library.defaultLanguageVersionMinor}"
+        "${kernel.defaultLanguageVersionMinor}"
         " does not match output from make_version.py ($major.$minor)";
   } else {
     print("Kernel version matches.");

pkg/front_end/test/spell_checking_list_code.txt

@@ -1124,6 +1124,7 @@ unshadowed
 unwraps
 unzip
 upcast
+update2018
 ur
 uri's
 url

pkg/front_end/tool/_fasta/generate_experimental_flags.dart

@@ -2,11 +2,7 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
-import 'dart:io';
-
-import 'dart:isolate';
+import 'dart:io' show File, Platform;
 
 import 'package:_fe_analyzer_shared/src/scanner/characters.dart'
     show $A, $MINUS, $a, $z;
@@ -15,23 +11,75 @@ import 'package:dart_style/dart_style.dart' show DartFormatter;
 
 import 'package:yaml/yaml.dart' show YamlMap, loadYaml;
 
-main(List<String> arguments) async {
-  var port = new ReceivePort();
-  await new File.fromUri(await computeGeneratedFile())
-      .writeAsString(await generateMessagesFile(), flush: true);
-  port.close();
+main(List<String> arguments) {
+  new File.fromUri(computeCfeGeneratedFile())
+      .writeAsStringSync(generateCfeFile(), flush: true);
+  new File.fromUri(computeKernelGeneratedFile())
+      .writeAsStringSync(generateKernelFile(), flush: true);
 }
 
-Future<Uri> computeGeneratedFile() {
-  return Isolate.resolvePackageUri(
-      Uri.parse('package:front_end/src/api_prototype/experimental_flags.dart'));
+Uri computeCfeGeneratedFile() {
+  return Platform.script
+      .resolve("../../lib/src/api_prototype/experimental_flags.dart");
 }
 
-Future<String> generateMessagesFile() async {
-  Uri messagesFile =
-      Platform.script.resolve("../../../../tools/experimental_features.yaml");
+Uri computeKernelGeneratedFile() {
+  return Platform.script
+      .resolve("../../../kernel/lib/default_language_version.dart");
+}
+
+Uri computeYamlFile() {
+  return Platform.script
+      .resolve("../../../../tools/experimental_features.yaml");
+}
+
+String generateKernelFile() {
+  Uri yamlFile = computeYamlFile();
   Map<dynamic, dynamic> yaml =
-      loadYaml(await new File.fromUri(messagesFile).readAsStringSync());
+      loadYaml(new File.fromUri(yamlFile).readAsStringSync());
+
+  int currentVersionMajor;
+  int currentVersionMinor;
+  {
+    String currentVersion = getAsVersionNumberString(yaml['current-version']);
+    List<String> split = currentVersion.split(".");
+    currentVersionMajor = int.parse(split[0]);
+    currentVersionMinor = int.parse(split[1]);
+  }
+
+  StringBuffer sb = new StringBuffer();
+
+  sb.write('''
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// NOTE: THIS FILE IS GENERATED. DO NOT EDIT.
+//
+// Instead modify 'tools/experimental_features.yaml' and run
+// 'pkg/front_end/tool/fasta generate-experimental-flags' to update.
+
+  int defaultLanguageVersionMajor = $currentVersionMajor;
+  int defaultLanguageVersionMinor = $currentVersionMinor;
+''');
+
+  return new DartFormatter().format("$sb");
+}
+
+String generateCfeFile() {
+  Uri yamlFile = computeYamlFile();
+  Map<dynamic, dynamic> yaml =
+      loadYaml(new File.fromUri(yamlFile).readAsStringSync());
+
+  int currentVersionMajor;
+  int currentVersionMinor;
+  {
+    String currentVersion = getAsVersionNumberString(yaml['current-version']);
+    List<String> split = currentVersion.split(".");
+    currentVersionMajor = int.parse(split[0]);
+    currentVersionMinor = int.parse(split[1]);
+  }
+
   StringBuffer sb = new StringBuffer();
 
   sb.write('''
@@ -53,16 +101,41 @@ Future<String> generateMessagesFile() async {
 
 enum ExperimentalFlag {
 ''');
-  for (var key in keys) {
+  for (String key in keys) {
     sb.writeln('  ${keyToIdentifier(key)},');
   }
   sb.write('''
 }
 
+''');
+
+  for (String key in keys) {
+    int major;
+    int minor;
+    String enabledIn =
+        getAsVersionNumberString((features[key] as YamlMap)['enabledIn']);
+    if (enabledIn == null) {
+      major = currentVersionMajor;
+      minor = currentVersionMinor;
+    } else {
+      List<String> split = enabledIn.split(".");
+      major = int.parse(split[0]);
+      minor = int.parse(split[1]);
+    }
+    sb.writeln('  const int enable'
+        '${keyToIdentifier(key, upperCaseFirst: true)}'
+        'MajorVersion = $major;');
+    sb.writeln('  const int enable'
+        '${keyToIdentifier(key, upperCaseFirst: true)}'
+        'MinorVersion = $minor;');
+  }
+
+  sb.write('''
+
 ExperimentalFlag parseExperimentalFlag(String flag) {
   switch (flag) {
 ''');
-  for (var key in keys) {
+  for (String key in keys) {
     sb.writeln('    case "$key":');
     sb.writeln('     return ExperimentalFlag.${keyToIdentifier(key)};');
   }
@@ -72,8 +145,8 @@ ExperimentalFlag parseExperimentalFlag(String flag) {
 
 const Map<ExperimentalFlag, bool> defaultExperimentalFlags = {
 ''');
-  for (var key in keys) {
-    var expired = (features[key] as YamlMap)['expired'];
+  for (String key in keys) {
+    bool expired = (features[key] as YamlMap)['expired'];
     bool shipped = (features[key] as YamlMap)['enabledIn'] != null;
     sb.writeln('  ExperimentalFlag.${keyToIdentifier(key)}: ${shipped},');
     if (shipped) {
@@ -87,7 +160,7 @@ const Map<ExperimentalFlag, bool> defaultExperimentalFlags = {
 
 const Map<ExperimentalFlag, bool> expiredExperimentalFlags = {
 ''');
-  for (var key in keys) {
+  for (String key in keys) {
     bool expired = (features[key] as YamlMap)['expired'] == true;
     sb.writeln('  ExperimentalFlag.${keyToIdentifier(key)}: ${expired},');
   }
@@ -96,10 +169,11 @@ const Map<ExperimentalFlag, bool> expiredExperimentalFlags = {
   return new DartFormatter().format("$sb");
 }
 
-keyToIdentifier(String key) {
-  var identifier = StringBuffer();
+keyToIdentifier(String key, {bool upperCaseFirst = false}) {
+  StringBuffer identifier = StringBuffer();
+  bool first = true;
   for (int index = 0; index < key.length; ++index) {
-    var code = key.codeUnitAt(index);
+    int code = key.codeUnitAt(index);
     if (code == $MINUS) {
       ++index;
       code = key.codeUnitAt(index);
@@ -107,7 +181,18 @@ keyToIdentifier(String key) {
         code = code - $a + $A;
       }
     }
+    if (first && upperCaseFirst && $a <= code && code <= $z) {
+      code = code - $a + $A;
+    }
+    first = false;
     identifier.writeCharCode(code);
   }
   return identifier.toString();
 }
+
+String getAsVersionNumberString(dynamic value) {
+  if (value == null) return null;
+  if (value is String) return value;
+  if (value is double) return "$value";
+  throw "Unexpected value: $value (${value.runtimeType})";
+}

pkg/front_end/tool/_fasta/generate_experimental_flags_test.dart

@@ -2,22 +2,35 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import "dart:io" show File;
-
-import "package:async_helper/async_helper.dart" show asyncTest;
-
-import "package:expect/expect.dart" show Expect;
+import "dart:io" show File, exitCode;
 
 import "generate_experimental_flags.dart"
-    show computeGeneratedFile, generateMessagesFile;
+    show
+        computeCfeGeneratedFile,
+        computeKernelGeneratedFile,
+        generateCfeFile,
+        generateKernelFile;
 
 main() {
-  asyncTest(() async {
-    Uri generatedFile = await computeGeneratedFile();
-    String generated = await generateMessagesFile();
-    String actual = (await new File.fromUri(generatedFile).readAsString())
+  {
+    Uri generatedFile = computeCfeGeneratedFile();
+    String generated = generateCfeFile();
+    String actual = (new File.fromUri(generatedFile).readAsStringSync())
         .replaceAll('\r\n', '\n');
-    Expect.stringEquals(generated, actual, """
+    check(generated, actual, generatedFile);
+  }
+  {
+    Uri generatedFile = computeKernelGeneratedFile();
+    String generated = generateKernelFile();
+    String actual = (new File.fromUri(generatedFile).readAsStringSync())
+        .replaceAll('\r\n', '\n');
+    check(generated, actual, generatedFile);
+  }
+}
+
+void check(String generated, String actual, Uri generatedFile) {
+  if (generated != actual) {
+    print("""
 ------------------------
 
 The generated file
@@ -28,5 +41,6 @@ is out of date. To regenerate the file, run
 
 ------------------------
 """);
-  });
+    exitCode = 1;
+  }
 }

pkg/kernel/lib/ast.dart

@@ -73,6 +73,8 @@ export 'visitor.dart';
 import 'canonical_name.dart' show CanonicalName;
 export 'canonical_name.dart' show CanonicalName;
 
+import 'default_language_version.dart';
+
 import 'transformations/flags.dart';
 import 'text/ast_to_text.dart';
 import 'core_types.dart';
@@ -329,10 +331,6 @@ class Library extends NamedNode
   /// The URI of the source file this library was loaded from.
   Uri fileUri;
 
-  // TODO(jensj): Do we have a better option than this?
-  static int defaultLanguageVersionMajor = 2;
-  static int defaultLanguageVersionMinor = 8;
-
   int _languageVersionMajor;
   int _languageVersionMinor;
   int get languageVersionMajor =>

pkg/kernel/lib/default_language_version.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// NOTE: THIS FILE IS GENERATED. DO NOT EDIT.
+//
+// Instead modify 'tools/experimental_features.yaml' and run
+// 'pkg/front_end/tool/fasta generate-experimental-flags' to update.
+
+int defaultLanguageVersionMajor = 2;
+int defaultLanguageVersionMinor = 8;